In recent years, mobile communications technologies have developed rapidly. Customers use mobile communications devices more frequently, for example, a portable phone, a portable phone that can access the Internet, a personal digital assistant, and other devices performing communication by using a dedicated communications network. A microphone, especially a micro-electro-mechanical system (MEMS) microphone, is one of the most important components in mobile communications devices.
The MEMS microphone is an electric transducer manufactured by using a micromechanical processing technology and has features such as a small volume, a good frequency response feature, and low noise. As electronic devices become smaller and thinner, MEMS microphones are widely applied to the devices.
An MEMS microphone in the related art includes a substrate having a back cavity and a capacitor system fixedly disposed on the substrate. The capacitor system includes a backplane and a vibrating diaphragm that are spaced apart from each other. The backplane includes a backplane insulation layer and a backplane conducting layer disposed on the backplane insulation layer.
However, in the related art, an outer edge of the backplane conducting layer is flush, an outline of the outer edge of the backplane conducting layer does not pass through any backplane hole. In an MEMS processing process, a crack occurs at a boundary between the backplane conducting layer and the backplane insulation layer, easily causing structural failure such as breaking of the backplane.
Therefore, it is desired to provide an improved MEMS microphone to resolve the foregoing problem.